Basement flue with no bottom clean out?

[NVHunter]

Ok,

We moved into a new to us home two weeks ago. I want to install a wood stove for supplemental heat and this house has a dual flue in the masonry chimney, one larger flue for the top level fireplace, and a second 7" X 11" terra-cotta flue for the daylight basement wood stove hookup requiring a thimble through the cinder block wall where a hole has been cut out.

I already had a thread regarding lining the smaller flue with a Stainless Steel liner so I've got those question out of the way, but now I have a new question.

With installing a new liner you install a T clean out at the bottom of the flue correct?

My question / concern is the smaller flue in the basement does not have an open bottom for a clean out. The flue stops at the opening in the cinder block wall where the thimble goes....

I stuck my camera up into the clean out in the bottom of the chimney outside and looked up the chimney. The smaller flue has a cinder block bottom sealing it completely up...

Is this a problem? Do I need a T clean out to install the stainless liner? If so, do I need to have a hole cut out of the bottom of this flue to make room for the T clean out?

Here are some pictures of the hole for the thimble, and pictures of the bottom of the fireplace and cinder block bottom of the smaller flue.

Mike

 

[webby3650]

I'm not sure what I'm looking at in the pics.
You do not need a clean out for the flue per say. But, you do need at least 2" of space below the thimble for the bottom of the Tee and Tee cap.

 

[NVHunter]

I'm not sure what I'm looking at in the pics.
You do not need a clean out for the flue per say. But, you do need at least 2" of space below the thimble for the bottom of the Tee and Tee cap.

Sorry I want to lable the pictures but didn't know how.

The pictures of the gray blocks are looking up at the bottom of the smaller flue where it's sealed off. I took these pictures from the clean out access at the bottom of the chimney.

The second picture of the black hole is from inside the house in the basement where the thimble will go. I was trying to show how it's full of debris and stops right there with no clean out at the bottom.

 

[webby3650]

Clean out all the debris so you can tell if there is any room below the thimble.

 

[bholler]

I believe that Technically to be to code you do need a clean out on a chimney servicing a solid fuel appliance needs to have a clean out. But i have never seen that enforced i would rather see a clean out and if possible we put one in but as long as you have enough drop for the bottom of the tee you should be ok.

 

[webby3650]

I believe that Technically to be to code you do need a clean out on a chimney servicing a solid fuel appliance needs to have a clean out. But i have never seen that enforced i would rather see a clean out and if possible we put one in but as long as you have enough drop for the bottom of the tee you should be ok.

Are saying that a Tee with a cap isn't up to code? I know that the original masonry chimney was supposed to have a clean out below the thimble, but once its retrofitted with a SS liner it's a sealed system servicing an appliance. I wouldn't be surprised if there is some silly out of date code that still requires a clean out. If that chimney needs cleaned, so does the connector pipe. It's easy to Pull the pipe and and clean out the Tee.

 

[bholler]

Are saying that a Tee with a cap isn't up to code? I know that the original masonry chimney was supposed to have a clean out below the thimble, but once its retrofitted with a SS liner it's a sealed system servicing an appliance. I wouldn't be surprised if there is some silly out of date code that still requires a clean out. If that chimney needs cleaned, so does the connector pipe. It's easy to Pull the pipe and and clean out the Tee.

Yes as far as i know it is still required by code. I still prefer to put them in when possible but I agree I don't feel it is necessary either because like you said the pipe should always come down anyway but you do want the drop of the tee so there is a little room for stuff to fall without obstructing the flow

 

[NVHunter]

Okay, I cleaned out the bottom of the flue. Its very uneven with mortar and chunks of cinder block throughout it. The deepest point below the thimble hole is 4-5" with a corner of a cinder block sticking out into the bottom of the flue 3" to 4". The corner of the cinder block is 1.5" below the thimble hole. I think I'm going to have to chisel the bottom of the flue out to make room for the tee and to make it more uniform and clean. It looks like they just threw a bunch of blocks and clay tiles together to build the interior of this damn thing...

As far as a clean out in the chimney, there is one below both flues. The fireplace flue is just sealed up, just as it would be if it had a stainless steel liner in it.


Here are a few photos of the flue.

One of the flue looking up with an offset of 20 degrees or so.

Two more of the thimble hole and the uneven floor of the flue...

Should I chisel it smooth?

Mike

 

[NVHunter]

No inquiries or thoughts on the pictures of the flue bottom?

 

[bholler]

No inquiries or thoughts on the pictures of the flue bottom?

We don't know how much your tee cap sticks down and if there is room for it or not. If you have room then no need to do anything if you dont you will need to chisel out some of that block. And yes it is a pita to do

 

[NVHunter]

Thanks, I don't mind hard work. Rather do a good job and pay attention to detail the first time then have to do it over again. I guess that's why I like to do things myself if I can, can't stand sub par work, which it looks like was done putting this flue in 40 years ago...

Thanks.

Mike

 

[bholler]

which it looks like was done putting this flue in 40 years ago...

I am not saying this to demean masons there are some fantastic masons out there but many have no clue how to properly build a chimney. And 40 years ago pretty much non of them did. Yours honestly is not bad at all for the time it was built that was pretty standard.

 

[Chinneysweep187]

Forgot about the clean out . They are important for masonry where the masonry will crumble and fall down . In your case I would say not needed when you get your liner measure tee with tee cap on and compare to size of thimble opening . If it won't make it I would just cut the bottom of the tee down to give you more room . As long as you check it every year you should be fine and clean it out when necessary. Get a slip connector for the tee to make disassembling easy .

 

[Chinneysweep187]

Also needs insulation for the liner fyi

 

[webby3650]

Forgot about the clean out . They are important for masonry where the masonry will crumble and fall down . In your case I would say not needed when you get your liner measure tee with tee cap on and compare to size of thimble opening . If it won't make it I would just cut the bottom of the tee down to give you more room . As long as you check it every year you should be fine and clean it out when necessary. Get a slip connector for the tee to make disassembling easy .

Only about an inch is gained by trimming the tee down. That will help, hope it's enough!

 

[bholler]

would just cut the bottom of the tee down to give you more room

You do realize that doing that voids the ul listing of the entire system. Not saying i haven't done it but only as a last resort if i cant clear enough space and never for a wood stove. There is going to be deposits in the chimney even if you are burning right and that space was put there by the people who designed the liner and its components to allow for a little bit of dirt buildup. I agree that a clean out is not necessary i still put them in when possible but they are not needed but i would not recommend cutting the tee for a wood stove

 

[bholler]

Also needs insulation for the liner fyi

Yes i agree totally

 

[NVHunter]

Yes i agree totally

Yes if there's not enough room at the bottom of the tee I will make room, ie: chisel out some space below for the tee to sit.

The tee and thimble all need to be insulated as well correct. Only makes sense I'd think. Is that what you were stating above Chimneysweep187?

I'm most likely going to use a 7" liner ovalize down to 4.5"x 9.1" or 5" x 8.75" for the inside 7"X11" diameter flue.

How much diameter does the insulation add to the liner? 1/2" insulation adds 1" correct? Rockford Chimney Supply states their 1/2" insulation adds 1.5". Is that true? If so where's the extra 1/2" coming from?

Thanks

 

[bholler]

You need to allow for 1.5" and it is going to be hard to get through those offsets

 

[NVHunter]

I looked at the fireplace inspection when we were buying the house. The sweep checked off that the woodstove flue is 8"x13".

I can't find the inside dimensions for an 8"x13" flue out there but I have found an 8.5"x13".

The spreadsheet stated that flues inside diameter is: 6 3/4" x 11 3/8".

Only oval flue I could feasible use would be the 4.5" x 9.1" which with insulation would be 6" x 10.6" which would give me 3/4" of play around the inside of the flue.... This looks to be the only insulated option I have.

That or break out the flue which you said could damage the fireplaces flue also. The two flue are pretty close together at the crown of the chimney.

I'm determined to put a stove in this house and it has to use this chimney....

Frustrating

 

[bholler]

Only oval flue I could feasible use would be the 4.5" x 9.1" which with insulation would be 6" x 10.6" which would give me 3/4" of play around the inside of the flue.... This looks to be the only insulated option I have.
That or break out the flue which you said could damage the fireplaces flue also. The two flue are pretty close together at the crown of the chimney.

I would have a good reputable sweep out and tell you if the tiles can be broken out it may be fine to break out. But that is not a diy job so you would have to get a quote for that. But yes that oval will fit it is just a question of whether you will be able to make it through the offsets or not. It may go right through What type of liner are you planning on using? Heavy flex or the mid weight stuff has a smaller od and is more flexible it generally goes through offsets better

 

[NVHunter]

I'll call around and have a few sweeps come out to see what they say. Is there any safety difference between the heavy flex or the mild weight liners?

 

[bholler]

It is not a safety issue it is more about durability. For customers who will be using their stove all the time we use heavy flex for occasional burners we will sometimes use mid weight we never use light wall for wood stoves but it can work fine we just prefer the heavier stuff with more metal and smooth walls.

 

[Chinneysweep187]

The liners I use can shave off about 2 or 3 inches cutting the bottom of the tee. Bholler I totally agree with you it's mostly for furnaces you should do that but if you can't make the room in the bottom of the thimble then I would do it. And your also right about a decent amount of build up in the chimney no matter what but I figured it'll it's a person doing this liner their self they would probably be the type to take the stove pipe off mid season and check for creosote which I always do at my house .

 

[Chinneysweep187]

In my opinions though if you can break the bottom of thimble out I would drop the liner with no tee cap and then everything would drop down to your normal clean out